Tickling the feet of diabetics to detect nerve damage could soon be replaced by an automated thermal imaging system to rapidly screen patients for “diabetic foot.”
The new technology, developed by Albuquerque startup VisionQuest Biomedical Inc., will be tested on about 400 diabetes patients at the University of New Mexico School of Medicine, paid for by a $3 million grant from the National Institutes of Health.
Foot-tickling, or tapping a tuning fork on patients’ feet, relies primarily on the skill of primary care physicians to detect problems, but they must send patients with potential nerve damage to specialists for definitive diagnosis, said Dr. Mark Burge, deputy director of UNM’s Clinical & Translational Science Center and a distinguished regents professor in the School of Medicine’s endocrinology division.
Replacing that old-school approach with a rapid and reliable technology-based diagnostic could allow a lot more diabetes patients to get tested for early signs of peripheral neuropathy – the disease that leads to sores, foot ulcers, and eventually amputation. And that, in turn, could allow more early intervention to slow the progression of “diabetic foot.”
“We want to diagnose problems sooner to evoke preventative strategies to avoid ulcers and amputation,” Burge told the Journal. “We need a simple diagnostic test that a general practitioner can do to identify feet at risk, rather than send patients to endocrinologists or neurologists.”
VisionQuest developed software to measure sense deterioration with infrared imaging based on how well patients regain feeling in their feet after a cold patch is applied to the skin, said VisionQuest founder and Chief Technology Officer Peter Soliz.
“Temperature tells if blood flow is there or not,” Soliz said. “Diabetics lose micro-vascular function, and the blood vessels start to clog up and die off, which leads to death of the nerves. So we image those vessels by looking at the thermal patterns that vessels show in the surface of the skin.”
After a cold patch is applied and removed, patients’ feet will warm up differently depending on nerve damage. Blood flow returns at different rates and in different patterns.
“With diabetics, the blood returns to the bottom of the foot in patches, with flickers here and there,” Soliz said. “We can quantify that and calculate how smooth the pattern is with algorithms to determine if there’s nerve damage.”
VisionQuest worked with Burge for about five years to develop the technology, including early testing on about 300 patients.
“Initial results from that preliminary work was promising,” Burge said. “The new grant will finance a clinical study over the next three years for definitive validation of the technology.”
After that, VisionQuest will pursue formal clinical trials for U.S. Food and Drug Administration clearance to go to market.
VisionQuest, which launched in 2008, has also developed rapid eye-screening technology to diagnose retinal disease in diabetics. It’s tested that technology on about 30,000 people in Mexico but still needs FDA clearance in the U.S.